title: A concerted mechanism for berberine bridge enzyme.
abstract: Berberine bridge enzyme catalyzes the conversion of (S)-reticuline to (S)-scoulerine by formation of a carbon-carbon bond between the N-methyl group and the phenolic ring. We elucidated the structure of berberine bridge enzyme from Eschscholzia californica and determined the kinetic rates for three active site protein variants. Here we propose a catalytic mechanism combining base-catalyzed proton abstraction with concerted carbon-carbon coupling accompanied by hydride transfer from the N-methyl group to the N5 atom of the FAD cofactor.
authors.affiliation: Institute of Biochemistry, Graz University of Technology, Petersgasse 12/II, 8010 Graz, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Winkler
authors.forename: Andrzej
authors.initials: A
authors.lastname: Lyskowski
authors.forename: Sabrina
authors.initials: S
authors.lastname: Riedl
authors.forename: Martin
authors.initials: M
authors.lastname: Puhl
authors.forename: Toni M
authors.initials: TM
authors.lastname: Kutchan
authors.forename: Peter
authors.initials: P
authors.lastname: Macheroux
authors.forename: Karl
authors.initials: K
authors.lastname: Gruber
mesh_terms: D000470:Alkaloids; D001600:Berberine Alkaloids; D002384:Catalysis; D020134:Catalytic Domain; D031675:Eschscholzia / Q000201:enzymology*; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D007700:Kinetics; D010089:Oxidoreductases, N-Demethylating / Q000737:chemistry / Q000378:metabolism; D010100:Oxygen; D011522:Protons
chemical_list: D000470:Alkaloids; D001600:Berberine Alkaloids; D011522:Protons; D005182:Flavin-Adenine Dinucleotide; C010941:discretamine; C071690:reticuline oxidase; D010089:Oxidoreductases, N-Demethylating; D010100:Oxygen